Disturbance. A rapid change in an environment that greatly alters a previously
persistent biological community

Diversity. A parameter describing, in combination, the species richness
and evenness of a collection of species. Diversity is often used as a synonym
for species richness

Diversity gradient. A regular change in diversity correlated with a geographic
space or gradient of some environmental factor

Ekman circulation. Movement of surface water at an angle from the wind,
as a result of the Coriolis effect

El Niño-Southern Oscillation (ENSO). Condition in which warm surface
water moves into the eastern Pacific, collapsing upwelling and increasing
surface-water temperatures and precipitation along the west coast of North
and South America

Emigration. The departure of individuals from a given area

Endosymbiotic. Being symbiotic and living within the body of an individual
of the associated species

Environmental stress. Variously defined as (a) an environmental change
to which an organism cannot acclimate and (b) an environmental change that
increases the probability of death

Epibenthic (epifaunal or epifloral). Living on the surface of the bottom

Epidemic spawning. Simultaneous shedding of gametes by a large number
of individuals

Epipelagic zone. The 0- to 150-m-depth zone, seaward of the shelf-slope
break

Epiphyte. Microalgal organism living on a surface (e.g., on a seaweed
frond)

Estuarine flow. Seaward flow of low-salinity surface water over a deeper
and higher -alinity layer

Estuarine realms. Large coastal water regions that have geographic continuity,are
bounded landward by a stretch of coastline with fresh-water input, and are
bounded seaward by a salinity front

Estuary. A semienclosed body of water that has a free connection with
the open sea and within which seawater is diluted measurably with freshwater
that is derived from land drainage

Euphausiid. Member of an order of holoplanktonic crustacea

Eutrophic. Water bodies or habitats having high concentrations of nutrients

Evenness. The component of diversity accounting for the degree to which
all species are equal in abundance, as opposed to strong dominance by one
or a few species

Fecal coliform bacteria Technically, all the facultative anaerobic gram negative
non-spore forming rod shaped bacteria that fermet lactose in EC medium with
gas production within 24h at 44.5 degrees C. A measure of bacteria mostly originating
from guts that enter waters. Believed to be correlated with disease-causing
(pathogenic) bacteria.

Fecal pellets. See Pellets

Fecundity. The number of eggs produced per female per unit time (often:
per spawning season)

Foliose coral. A coral whose skeletal form approximates that of a broad,
flattened plate

Food chain. An abstraction describing the network of feeding relationships

in a community as a series of links of trophic levels, such as primary
producers, herbivores, and primary carnivores

Food chain efficiency. Amount of energy of some other quantity extracted
from a trophic level, divided by the amount of energy produced by the next-lower
trophic level

Food web. A network describing the feeding interactions of the species
in an area

Foraminifera. Protozoan group, individuals of which usually secrete a
calcareous test; both planktonic and benthic representatives

Founder principle. A small colonizing population is genetically unrepresentative
of the source of population

Freshet. An increase of water flow into an estuary during the late winter
or spring, owing to increased precipitation and snow melt in the watershed

Front. A major discontinuity separating ocean currents and water masses
in any combination

Fugitive species. A species adapted to colonize newly disturbed habitats